Terminal connection joint and terminal block

ABSTRACT

A terminal block includes a terminal portion having an end surface formed with a screw hole and a peripheral surface, a terminal connection joint including a tubular portion having an inner peripheral surface which faces the peripheral surface of the terminal portion, a contact portion having a first contact surface which comes into contact with the end surface of the terminal portion and a second contact surface which comes into contact with a plate-like terminal and a clamping portion for clamping the plate-like terminal between the contact portion and the clamping portion, a fixing bolt including an externally threaded portion to be threadably engaged with the screw hole and a head portion for pressing the clamping portion in a direction to press the plate-like terminal. The contact portion is configured to press the plate-like terminal by being elastically supported on the tubular portion.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a terminal connection joint and aterminal block.

2. Background Art

There is conventionally known a terminal block configured such that aterminal is fixed by being clamped between a flange portion formed on abase end part of a contact bolt and a nut threadably engaged with thecontact bolt as disclosed in Japanese Unexamined Patent Publication No.2007-207494.

In a configuration for fixing a terminal by a fastening force of a boltand a nut (fastening portion) as in the terminal block disclosed inJapanese Unexamined Patent Publication No. 2007-207494, the nut may begradually loosened by being continuously subjected to vibration, forexample, in the case of use in an air plane. Thus, a contact areabetween the fastening portion and the terminal may possibly decrease toincrease an electrical resistance.

SUMMARY OF THE INVENTION

An object of the present invention is to prevent an increase inelectrical resistance even if a fastening force of a fastening portionis weakened.

One aspect of the present invention is directed to a terminal block,including a terminal portion having an end surface formed with a screwhole and a peripheral surface, a terminal connection joint including atubular portion having an inner peripheral surface which faces theperipheral surface of the terminal portion, a contact portion having afirst contact surface which comes into contact with the end surface ofthe terminal portion and a second contact surface which comes intocontact with a plate-like terminal and a clamping portion for clampingthe plate-like terminal between the contact portion and the clampingportion, and a fastening portion including an externally threadedportion to be threadably engaged with the screw hole and a pressingportion for pressing the clamping portion in a direction to press theplate-like terminal. The contact portion is configured to receive apressing force by the pressing portion while being elastically supportedon the tubular portion.

Another aspect of the present invention is directed to a terminalconnection joint for electrically connecting a terminal portion providedon a terminal block and a plate-like terminal, including a tubularportion having an inner peripheral surface which faces a peripheralsurface of the terminal portion, a contact portion having a firstcontact surface which comes into contact with an end surface of theterminal portion and a second contact surface which comes into contactwith a plate-like terminal, and a clamping portion for clamping theplate-like terminal between the contact portion and the clampingportion. The contact portion is configured to press the plate-liketerminal by being elastically supported on the tubular portion.

These and other objects, features and advantages of the presentdisclosure will become more apparent upon reading the following detaileddescription along with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a terminal block according to anembodiment of the present invention,

FIG. 2 is a perspective view enlargedly showing a connecting part of aterminal portion and a plate-like terminal in the terminal block,

FIG. 3 is a perspective view of a terminal connection joint, and

FIG. 4 is a sectional view along line IV-IV of FIG. 2.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a mode for carrying out the present invention is describedin detail with reference to the drawings.

A terminal block 10 according to this embodiment is a terminal block forelectrically connecting a control device to be installed in an air planeand a power supply thereof. As shown in FIG. 1, the terminal block 10includes a base 12, terminal portions 14 fixed to the base 12, aterminal connection joint 16 for attaching a plate-like terminal 20 tothe terminal portion 14, and a fixing bolt 18 for fixing the terminalconnection joint 16.

The base 12 is in the form of a rectangular flat plate long in onedirection. A plurality of terminal portions 14 are juxtaposed in alongitudinal direction of the base 12. The middle terminal portion 14 isformed to be taller than the terminal portions 14 on opposite ends.Insertion holes 12 a, through which unillustrated bolts for fixing thebase 12 to an unillustrated fixing body are inserted, are formed on endparts of the base 12. Note that there is no limitation to theconfiguration that the middle terminal portion 14 is taller than theterminal portions 14 on the opposite ends.

Each terminal portion 14 is fixed to the base 12 while penetratingthrough the base 12 in a thickness direction. The terminal portion 14 isformed into a cylindrical shape as a whole and stably supported on thebase 12 by being held in a holding portion 22 provided on the base 12. Atip surface (upper end surface) of the terminal portion 14 is formed tobe flat and a screw hole 14 a extending in an axial direction is formedin a central part of the tip surface. This screw hole 14 a serves as aninternal thread. Note that the terminal portion 14 needs not be formedinto a cylindrical shape and only has to have a peripheral surface. Forexample, the terminal portion 14 may be formed into a prismatic shape.

The plate-like terminal 20 is a terminal in the form of a thin andslender flat plate and has flexibility. Either the terminal portions 14or the plate-like terminal 20 are/is connected to the control device andthe other(s) is/are connected to the power supply for the controldevice.

As shown in FIGS. 2 to 4, the terminal connection joint 16 includes atubular portion 31, a receiving portion 32 and a clamping portion 33.The tubular portion 31 is a part which is formed into a cylindricaltubular shape and covers a peripheral surface 14 b of the cylindricalterminal portion 14 entirely in a circumferential direction. An innerperipheral surface 31 a of the tubular portion 31 faces the peripheralsurface 14 b of the terminal portion 14. The tubular portion 31 isformed by rolling a plate-like member into a cylindrical tubular shape.In this embodiment, the tubular portion 31 is formed into a cylindricaltubular shape as a whole by causing semicylindrical tubular membersrespectively connected to the lower ends of a pair of extending portions32 a to be described later to face each other. Note that the shape ofthe tubular portion 31 is not limited to a cylindrical tubular shape andonly has to have an inner peripheral surface. For example, if theterminal portion 14 is formed into a prismatic shape, the tubularportion 31 may be formed into a prismatic tubular shape.

The receiving portion 32 is formed by bending parts respectivelyextending from two parts (semicylindrical tubular parts) facing eachother at an end part (upper end part) of the tubular portion 31 indirections toward each other. Specifically, the receiving portion 32includes a pair of extending portions 32 a, 32 a extending obliquelytoward opposite sides from the two parts facing each other at the endpart of the tubular portion 31, a pair of bent portions 32 b, 32 bfolded at end parts of the pair of extending portions 32 a, 32 a toextend in opposite directions, and a contact portion 32 c formed into arectangular planar shape perpendicular to the axial direction(longitudinal direction) of the terminal portion 14 and long in onedirection to connect the both bent portions 32 b, 32 b. Specifically,the opposite longitudinal ends of the contact portion 32 c are connectedto the tubular portion 31 via the bent portions 32 b and the extendingportions 32 a.

Since the receiving portion 32 is bent substantially by 180° at the bentportions 32 b, the contact portion 32 c thereof receives a bendingelastic force of a plate material acting upward in FIG. 4. Specifically,the extending portions 32 a and the bent portions 32 b form an elasticsupporting portion for elastically supporting the contact portion 32 c.Thus, the contact portion 32 c presses the plate-like terminal 20 upward(first direction) by an elastic force.

A projecting portion 31 b projecting radially inwardly is provided on alower end part of the tubular portion 31 (end part opposite to thereceiving portion 32). The projecting portion 31 b is formed by bendingthe lower end part of the tubular portion 31 inwardly. This projectingportion 31 b is inserted into a recessed groove 14 c as a recess formedon the peripheral surface 14 b of the terminal portion 14. Specifically,if the terminal connection joint 16 is moved downward in assembling theterminal connection joint 16 with the terminal portion 14, theprojecting portion 31 b of the tubular portion 31 is fitted into therecessed groove 14 c of the terminal portion 14, wherefore the terminalconnection joint 16 is positioned and fixed to the terminal portion 14.

The clamping portion 33 is formed into a rectangular planar shapeparallel to the contact portion 32 c of the receiving portion 32 andlong in the one direction. Specifically, the clamping portion 33 isformed by bending clamping extending portions 33 a in directions towardeach other. The clamping extending portions 33 a are extending fromopposite end parts of the contact portion 32 c of the receiving portion32 in a direction (width direction) perpendicular to the longitudinaldirection. Since the clamping extending portions 33 a respectivelyextending from the opposite sides of the receiving portion 32 are bentin the directions toward each other, tip parts thereof are in contactwith each other. Note that although the clamping extending portions 33 arespectively extend from the opposite end parts of the receiving portion32 in the width direction and are bent in the shown example, there is nolimitation to this. For example, a clamping extending portion 33 a mayextend from one end part of the receiving portion 32 in the widthdirection and be bent. In this case, the clamping extending portion 33 aextends while having the same area as the receiving portion 32 and beingparallel to the receiving portion 32.

To form the terminal connection joint 16, the clamping extendingportions 33 a extending from the opposite end parts (opposite end partsin the width direction) of a part forming the contact portion 32 c ofthe receiving portion 33 are bent upward in FIG. 3 so as to face eachother and the bent portions 32 b and the extending portions 32 aextending from the opposite end parts (opposite end parts in thelongitudinal direction) of the part forming the contact portion 32 c ofthe receiving portion 33 are bent downward in FIG. 3. Since thesemicylindrical tubular parts are respectively formed on the tips ofthese extending portions 32 a, the bent portions 32 b and the extendingportions 32 a only have to be so bent that the semicylindrical tubularparts face each other to form a tubular shape.

An end part of the plate-like terminal 20 is inserted into a spacebetween the receiving portion 32 and the clamping portion 33 of theterminal connection joint 16. A lower surface (back side surface) 32 eof the contact portion 32 c of the receiving portion 32 is in contactwith the tip surface of the terminal portion 14 and an upper surface(front side surface) 32 f of the contact portion 32 c of the receivingportion 32 is in contact with the plate-like terminal 20. Specifically,the lower surface 32 e of the contact portion 32 c of the receivingportion 32 serves as a first contact surface which comes into contactwith the tip surface of the terminal portion 14 and the upper surface 32f of the contact portion 32 c of the receiving portion 32 serves as asecond contact surface which comes into contact with the plate-liketerminal 20.

A lower surface (back side surface) 33 c of the clamping portion 33serves as a contact surface which comes into contact with the plate-liketerminal 20 and an upper surface (front side surface) 33 d of theclamping portion 33 serves as a pressed surface to be pressed by a headportion 18 b of the fixing bolt 18 via a washer 36.

Since the clamping portion 33 is pressed from above by the fixing bolt18, the lower surface 33 c of the clamping portion 33 presses theplate-like terminal 20 downward (second direction opposite to the firstdirection). The receiving portion 32 receives a pressing force by theclamping portion 33 via the plate-like terminal 20.

An insertion hole 32 d (see FIG. 4), through which an externallythreaded portion 18 a of the fixing bolt 18 is inserted, is formed in acentral part of the receiving portion 32. Further, an insertion hole 33b (see FIG. 4), through which the externally threaded portion 18 a ofthe fixing bolt 18 is inserted, is formed in a central part of theclamping portion 33.

The terminal connection joint 16 is formed of one plate material.Specifically, opposite end parts (first parts) of the plate material arerespectively bent into a semicylindrical tubular shape. Then, a part(second part) connected to base end parts of the first parts of theplate material is so bent that concave surfaces of these semicylindricaltubular shapes face each other to form the receiving portion 32, wherebya cylindrical tubular part is formed by the semicylindrical tubularparts. In this way, the tubular portion 31 is formed. Then, parts (thirdparts) extending from the opposite sides of the receiving portion 32 inthe width direction are bent to form the clamping portion 33. In thisway, the terminal connection joint 16 can be formed of one platematerial.

As shown in FIG. 4, a ring-shaped coil spring 38 is interposed betweenthe inner peripheral surface 31 a of the tubular portion 31 and theterminal portion 14. Specifically, a circumferentially extending groove14 d is formed on the peripheral surface 14 b of the terminal portion 14entirely in the circumferential direction, and the coil spring 38 isarranged in this groove 14 d. Although FIG. 4 shows an example in whichthe tubular portion 31 and the terminal portion 14 are in contact viathe coil spring 38 and the tubular portion 31 and the terminal portion14 are not directly in contact, the tubular portion 31 and the terminalportion 14 may be directly in contact instead of this. It is madedifficult for the tubular portion 31 to move relative to the terminalportion 14 by arranging the coil spring 38 between the tubular portion31 and the terminal portion 14.

The fixing bolt 18 functions as a fastening portion including theexternally threaded portion 18 a to be threadably engaged with the screwhole 14 a and the head portion 18 b as a pressing portion formed on anend part of the externally threaded portion 18 a. The head portion 18 bpresses the clamping portion 33 in a direction to press the plate-liketerminal 20 via the washer 36. As the fixing bolt 18 is screwed into thescrew hole 14 a of the terminal portion 14, the head portion 18 b of thefixing bolt 18 presses the clamping portion 33 from above via the washer36, whereby the plate-like terminal 20 presses the contact portion 32 cof the receiving portion 32 from above. Thus, the contact portion 32 cis displaced downward while the bent portions 32 b and the extendingportions 32 a are elastically deformed, and the contact portion 32 ccomes into contact with the tip surface of the terminal portion 14.Specifically, the contact portion 32 c is supported in a state where thebent portions 32 b and the extending portions 32 a are elasticallydeformed. Thus, the plate-like terminal 20 receives an elastic force bythe contact portion 32 c from below while receiving a fastening force bythe fixing bolt 18 from above.

As described above, in this embodiment, the externally threaded portion18 a of the fixing bolt 18 is threadably engaged with the screw hole 14a of the terminal portion 14, whereby the clamping portion 33 of theterminal connection joint 16 can be pressed by the head portion 18 b ofthe fixing bolt 18. This causes the clamping portion 33 to press onesurface (upper surface in FIG. 4) of the plate-like terminal 20.Further, the contact portion 32 c of the terminal connection joint 16 iselastically supported on the tubular portion 31 to press another surface(lower surface in FIG. 4) of the plate-like terminal 20. In this way, acontact between the terminal connection joint 16 and the terminalportion 14 is ensured by the fastening force by the screw and theelastic force for supporting the contact portion 32 c. In addition,since the plate-like terminal 20 is pressed by the elastic force fromthe side opposite to the fastening force by the screw, even if thefastening force of the screw is weakened due to continuous subjection tovibration, the contact between the clamping portion 33 and theplate-like terminal 20 and the contact between the contact portion 32 cand the plate-like terminal 20 are ensured by the elastic force. Thus,the electrical resistance is not increased due to a reduction in thecontact area and heat generation due to an increase in the electricalresistance can be prevented.

Further, since the projecting portion 31 b of the tubular portion 31 isinserted into the recessed groove 14 c of the terminal portion 14 inthis embodiment, the terminal connection joint 16 is locked to theterminal portion 14. Thus, the terminal connection joint 16 does notaxially move relative to the terminal portion 14, wherefore thedetachment of the terminal connection joint 16 can be prevented.

Further, since the coil spring 38 is interposed between the tubularportion 31 and the terminal portion 14 in this embodiment, it is madedifficult for the terminal connection joint 16 to move relative to theterminal portion 14. Thus, the terminal connection joint 16 can bestably held.

Further, since the terminal connection joint 16 is formed of one platematerial in this embodiment, an increase in the number of componentsconstituting the terminal block 10 can be suppressed and, in addition,an assembling operation of the terminal block 10 can be simplified.

Note that the present invention is not limited to the above embodimentand various changes, improvements and the like can be made withoutdeparting from the gist thereof. For example, although the terminalconnection joint 16 is formed of one plate material in the aboveembodiment, there is no limitation to this. The terminal connectionjoint 16 may be formed by separately forming a tubular portion 31, acontact portion 32 c and an elastic supporting portion for elasticallysupporting the contact portion 32 c and then assembling them with eachother.

Although the fixing bolt 18 includes the externally threaded portion 18a and the head portion 18 b in the above embodiment, there is nolimitation to this. The fastening portion may include the externallythreaded portion 18 a and a nut to be threadably engaged with thisexternally threaded portion 18 a. In this configuration, the nut pressesthe clamping portion 33 via the washer 36 by being tightened. Note thatthe washer 36 may be omitted.

Here, the above embodiment is summarized.

(1) In the above embodiment, the externally threaded portion of thefastening portion is threadably engaged with the screw hole of theterminal portion, whereby the clamping portion of the terminalconnection joint can be pressed by the pressing portion of the fasteningportion. This causes the clamping portion to press one surface of theplate-like terminal. Further, the contact portion of the terminalconnection joint is elastically supported on the tubular portion havingthe inner peripheral surface facing the peripheral surface of theterminal portion, and the other surface of the plate-like terminal ispressed. In this way, the contact between the terminal connection jointand the terminal portion is ensured by the fastening force by the screwand the elastic force for supporting the contact portion. In addition,since the plate-like terminal is pressed by the elastic force from theside opposite to the fastening force by the screw, even if the fasteningforce of the screw is weakened due to continuous subjection tovibration, the contact between the clamping portion and the plate-liketerminal and the contact between the contact portion and the plate-liketerminal are ensured by the elastic force. Thus, the electricalresistance is not increased due to a reduction in the contact area andheat generation due to an increase in the electrical resistance can beprevented.

(2) In the above terminal block, the projecting portion may be formed onthe end part of the tubular portion opposite to the contact portion bybeing bent toward an inner peripheral surface side. In this case, theprojecting portion may be inserted into the recess formed on theperipheral surface of the terminal portion.

Since the projecting portion is inserted in the recess in this mode, theterminal connection joint is locked to the terminal portion. Thus, theterminal connection joint does not axially move relative to the terminalportion, wherefore the detachment of the terminal connection joint canbe prevented.

(3) The ring-shaped coil spring may be interposed between the tubularportion and the terminal portion.

In this mode, the coil spring is interposed between the tubular portionand the terminal portion, thereby making it difficult for the terminalconnection joint to move relative to the terminal portion. Thus, theterminal connection joint can be stably held.

(4) The terminal connection joint may be formed of one plate material.

In this mode, an increase in the number of components constituting theterminal block can be suppressed and, in addition, the assemblingoperation of the terminal block can be simplified.

(5) In the above embodiment, the terminal connection joint forelectrically connecting the terminal portion provided on the terminalblock and the plate-like terminal includes the tubular portion havingthe inner peripheral surface that faces the peripheral surface of theterminal portion, the contact portion having the first contact surfacethat comes into contact with the end surface of the terminal portion andthe second contact surface that comes into contact with the plate-liketerminal, and the clamping portion for clamping the plate-like terminalbetween the contact portion and the clamping portion. The contactportion is configured to press the plate-like terminal by beingelastically supported on the tubular portion.

(6) In the terminal connection joint, the projecting portion may beformed on the end part of the tubular portion opposite to the contactportion by being bent toward the inner peripheral surface side.

(7) The terminal connection joint may be formed of one plate material.

As described above, according to this embodiment, even if the fasteningforce of the fastening portion is weakened, an increase in electricalresistance can be prevented.

This application is based on Japanese Patent application No. 2012-270206filed in Japan Patent Office on Dec. 11, 2012, the contents of which arehereby incorporated by reference.

Although the present invention has been fully described by way ofexample with reference to the accompanying drawings, it is to beunderstood that various changes and modifications will be apparent tothose skilled in the art. Therefore, unless otherwise such changes andmodifications depart from the scope of the present invention hereinafterdefined, they should be construed as being included therein.

1. A terminal block, comprising: a terminal portion having an endsurface formed with a screw hole and a peripheral surface; a terminalconnection joint including a tubular portion having an inner peripheralsurface which faces the peripheral surface of the terminal portion, acontact portion having a first contact surface which comes into contactwith the end surface of the terminal portion and a second contactsurface which comes into contact with a plate-like terminal and aclamping portion for clamping the plate-like terminal between thecontact portion and the clamping portion; and a fastening portionincluding an externally threaded portion to be threadably engaged withthe screw hole and a pressing portion for pressing the clamping portionin a direction to press the plate-like terminal; the contact portionbeing configured to receive a pressing force by the pressing portionwhile being elastically supported on the tubular portion.
 2. A terminalblock according to claim 1, wherein: a projecting portion is formed onan end part of the tubular portion opposite to the contact portion bybeing bent toward an inner peripheral surface side; and the projectingportion is inserted into a recess formed on the peripheral surface ofthe terminal portion.
 3. A terminal block according to claim 1, wherein:a ring-shaped coil spring is interposed between the tubular portion andthe terminal portion.
 4. A terminal block according to claim 1, wherein:the terminal connection joint is formed of one plate material.
 5. Aterminal connection joint for electrically connecting a terminal portionprovided on a terminal block and a plate-like terminal, comprising: atubular portion having an inner peripheral surface which faces aperipheral surface of the terminal portion; a contact portion having afirst contact surface which comes into contact with an end surface ofthe terminal portion and a second contact surface which comes intocontact with the plate-like terminal; and a clamping portion forclamping the plate-like terminal between the contact portion and theclamping portion; the contact portion being configured to press theplate-like terminal by being elastically supported on the tubularportion.
 6. A terminal connection joint according to claim 5, wherein: aprojecting portion is formed on an end part of the tubular portionopposite to the contact portion by being bent toward an inner peripheralsurface side.
 7. A terminal connection joint according to claim 5,wherein: the terminal connection joint is formed of one plate material.